


denaturation

by nardis



Category: Haikyuu!!
Genre: Angst, Based on a True Story, Haikyuu Angst Week 2020, M/M, Miscommunication, Ouch, Pining, Unrequited Love, i don't want to say based on a true story but, lots of metaphors
Language: English
Status: Completed
Published: 2020-11-08
Updated: 2020-11-08
Packaged: 2021-03-08 23:34:59
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,531
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27444979
Author URL: https://archiveofourown.org/users/nardis/pseuds/nardis
Summary: denaturation (biochemistry): the process in which proteins or nucleic acids lose their structure by application of some external stress or heator: sakusa kiyoomi's story of burning and falling apart
Relationships: Miya Atsumu/Sakusa Kiyoomi
Comments: 18
Kudos: 86
Collections: Haikyuu Angst Week 2020





	denaturation

**Author's Note:**

> hi!! thank u for clicking on this!! this is my late-ish angst week entry, and it's kinda just me retelling one of my own shitty love stories thru the eyes of my two favorite jerks. i hope i was able to do the two of them justice and incorporate some of that sakuatsu magic in here. i hope u enjoy!!!

Kiyoomi’s mother had once told him about how heat kills germs.

“Once you get them hot enough, the proteins in them start to break apart, and then they can’t function, so they can’t do anything to you anymore. Alright, Ki?” 

He didn’t fully understand it at the time, and he still doesn’t now, but that night he had sat in front of the stovetop, seeing just how close he could get his hands to the flame before his palms started to sting, hoping in his head that the flames would be hot enough to grant him immunity from the rest of the world. 

Looking back now, he thinks it’s the same way with Miya Atsumu. 

Seeing him in the center of the MSBY gym for the first time since high school almost made him turn around and walk out. The image of Miya snarling at him, calling him a scrub through the net at nationals sat fresh in his mind.

He knew there were other teams out there, other teams with offers just as good and players just as smart, so why should he stay and put up with this?

But he did. He didn’t know if it was the Osaka air, a hint cleaner than Tokyo’s, or the fact that Miya’s smile seemed softer than it was in high school, but he had pulled up his face mask and headed straight to the locker room, trying to mentally review the directions to his new apartment instead of visualizing pale blonde hair and hooded eyes.

He learns, over months of quiet practices at dawn and crowded games at sunset, that Miya Atsumu is one of the least charming people that he’s ever met. He learns, unfortunately, that a box of toner and a sparse amount of hair gel can’t fix a sour personality that’s been brewing for 23 years.

And yet he finds himself stuck to his side more often than not. 

On Miya’s better days, he’s one of the best setters in Japan. He’s precise and picky, but his expectations are set so high that it forces the best out of everyone he meets. On his worse days, he’s just Miya Atsumu, 23. He’s Miya Osamu’s meaner, angrier, _lesser_ , half, and he’ll either bring you down with him or bring himself so far down that only a miracle can get him out.

But throughout all this, he shines. He’s a million times brighter and hotter than any stovetop flame that Kiyoomi’s ever sat in front of, and he finds himself getting closer and closer each day, watching his palms turn red with his presence.

He thinks, _maybe if I get close enough, there will be a flaw hiding deep near his spark_ . He hopes, _maybe if I let myself burn, I can finally stop being drawn to his side._

Miya’s unique in the way that he manages to acknowledge his boundaries unlike other people do, with a kindness he poorly disguises. At the cost of his kindness, he’ll try to chip away at Kiyoomi’s boundaries, careful like a child with a sledgehammer.

It starts, abruptly, with a firm hand on his shoulder in the middle of a match with the Red Falcons, and it throws him off so much that it almost costs them the set. He knows that he meant well, but he also knows his limits, and he spends the next hour sending him a glare so cold that it could put his fire out. 

It starts there, and it doesn’t stop. 

They exchange numbers. Miya starts texting him past midnight, anything from dog pictures to a complainant about something that Bokuto had said earlier that day. He’ll call him sometimes, tell him a stupid story that Kiyoomi finds himself caring about too much before he insists they go to bed.

He starts letting himself get dragged along to get drinks with the team after games. He’ll even drink alongside everyone, adding his dry contributions to whatever subjects their gathering of drunk volleyball players wants to explore that night.

And eventually, Miya starts showing up at his apartment. He protests that he’s clean and showered, twice _,_ and holds up a small bag of food from his brother’s restaurant in one hand, and a few DVD copies of V-League games in the other. His hair is still wet but his eyes are bright and wide, and they manage to lower Kiyoomi’s defenses in an instant. In this moment of weakness, he makes him put on slippers, and he lets him inside.

Kiyoomi knows he’s getting too close, knows that his skin is starting to crack and blister, but he can’t bring himself to pull away. He thinks, _maybe this warmth will kill the itch under my skin._

Miya has made a place in his life. _Atsumu_ has made a place in his life. He’s set up his stupid blonde fire right outside of Kiyoomi’s front door and makes sure to douse it with gas every single time they interact.

Now, they walk together to and from practices. They exchange water bottles and tape each other’s hands, an intimacy that he's unfamiliar to, and Kiyoomi wonders to himself if this is what it’s like to truly have someone enjoy his presence, no strings attached. 

He wonders to himself on their days off when Atsumu starts to compile a list of movies that he proclaims are masterpieces Kiyoomi can’t live without seeing, and stops wondering once the world melts away from around them, as they sit down on his couch with two mugs of Kiyoomi’s favorite tea and Atsumu’s movie of choice.

Atsumu calls him late at night, almost every other night, to complain about Osamu or to talk about some stupidly impossible volleyball trick he wants to try. They’ll get off-topic an hour in, and manage to both fall asleep before the end call button gets pressed. 

Kiyoomi, alone, cooks what he knows is too much food, and he texts Atsumu complaining about leftovers being unpleasant, complaining that they can’t keep eating only onigiri he siphons off his twin. Inviting him in.

Kiyoomi stops thinking about fires on stovetops and outside of his door.

Kiyoomi stops noticing how he burns.

-

It isn’t until he’s on the phone with Komori while Atsumu is away in Hyogo that he realizes just how bad it is.

“How’s Hiroshima?” he asks, at a lack for better conversation.

There’s a crack of static before he can hear Komori’s reply. “It’s good, but I do miss how crowded it is back home sometimes.”

He cringes at the thought of Tokyo’s busy streets. It’s one thing he doesn’t miss. “Lucky you.” 

Komori laughs, stopping to take a breath. “God, I miss you sometimes.” He adds, quieter.

In the emptiness of his apartment, he lets the corner of his lip twitch up. “Yeah. Me too.”

They sit in silence, taking in the single familial moment they let themselves share barely once a year.

“So,” Komori cuts in, and he can hear the smirk in his voice, “Suna mentioned that you’ve been hanging around Miya Atsumu?”

He groans. Komori chuckles on the other side of the line.

“Maybe.”

“How the hell did that happen?” He asks, trying to smother bits of his laughter.

Kiyoomi stops to think. How _did_ it happen? More importantly, how did the aspects of his daily life make it across Japan to Suna Rintarou, of all people?

His voice slows. “I don’t know.”

“Sure you don’t.” Komori pushes back.

He sighs, loud enough to make a point. “We’re on the same team. Is hanging out with a teammate a crime?”

“Don’t be dramatic,” Komori replies, exasperated. “You’re just not a ‘hanging out’ type of person, I was surprised.”

“And what if I am?” He pauses. “A hanging out person.”

There’s a long silence on Komori’s end. A breath.

“Sakusa,” He starts, dead serious, “Are you two dating?”

Kiyoomi freezes. It feels like the world around him freezes too, and he sucks in a breath. Distantly, he hears the clicking of a gas stove and the wisps of a flame. He feels the palms of his hands start to itch and turn red.

Komori clears his throat, loudly. “Sakusa. Sakusa? Are you still there? Did I kill you?” 

“I’m here,” he states after a minute of heavy breathing, his voice cracking at the end. “You didn’t kill me.”

Komori laughs, light, but he can hear the strain of concern seeping through the edges. “Good to know.”

“We aren’t dating.” He says, uncertain. “At least, we’ve never really talked about it.” Komori’s silent, so he continues. “I just thought he was like that around his friends.”

“Suna mentioned that he talks about you,” Komori adds, unhelpfully. 

He’s quiet. The slippers that Atsumu keeps for himself in the doorway stare at him like an accusation. He wonders if he’s the proteins now, and the heat of Miya Atsumu is making him lose his structure.

“Fuck.” 

“Yeah.” Komori parrots, softly. He stops. There’s a muffled sound in the background, and lets out a defeated sigh. “Fuck, I’ve gotta head out, okay? I’m sorry for the bad timing, but you better keep me updated on everything.”

He sighs. “I will.” 

“Good. You better.”

He makes a small noise in response, and the call cuts off, leaving Kiyoomi alone in his apartment. He takes his phone and sets it face down on the table, standing up to wash his hands in the kitchen sink, like trying to clean the conversation off of him. He sits back down, props his elbows on the table, and digs his palms into his eyes so hard that he sees colors.

He wishes his mother were here to explain the science behind this. Behind newfound infatuation. Behind Miya Atsumu.

-

There’s a week after Atsumu returns from Hyogo of back to back practices and games, and Kiyoomi barely has any time to let himself think about how Atsumu apparently likes to talk about their moments to people, or how the burning has moved from his palms to his cheeks. 

He’s tired past the point of exhaustion, his wrists have been aching for days, and he wishes that he could just lay down in the middle of the court and pretend like he was still a star-studded teenager, not an adult losing sleep over one of the biggest idiots in the entire V-League.

Once they finally get a day off, Atsumu is right at his door that evening as expected, damp hair and all, and he smiles at him so bright that Kiyoomi wants to forget everything that he talked about with Komori and continue living in their crafted limbo. 

Atsumu hands him a bag of onigiri and takes his shoes off, sliding on his own pair of slippers before he walks any further into his apartment. 

“Omi, I’m just gonna go with a random movie today, I’m fuckin’ exhausted,” Atsumu says, glancing over at him. 

“If you’re exhausted, why are you here?” He replies, trying to ignore the whispers of Komori’s voice in the back of his head, his _‘Are you two dating?_ ’ running on a constant loop. 

Atsumu scoffs and goes to kneel in front of the TV, fiddling with the plastic cases in his hand. He doesn’t look up. “Fuck off, y'know you’d be sad without me.”

“Miserable.” he deadpans, and moves to the kitchen to heat some water for tea. 

Atsumu finishes putting in the disc of the night and he turns around to look at Kiyoomi as he’s grabbing mugs and tea bags for both of them. His signature grin is plastered onto his face. “Speakin’ of being sad without me, what’d you do while I was gone last week?”

“Cried and waited for you to knock on my door, apparently.” He replies, visualizing the color behind closed eyes, and Atsumu barks out a laugh.

“Knew it.”

They get everything settled and move to his couch, Kiyoomi taking control of the remote and Atsumu grabbing them both their respective onigiris, which he knows by now are double wrapped and prepared with gloves by his brother at Atsumu’s request.

He presses play, trying his best to let the sounds of the TV drown out the sound of Komori’s voice that’s taken up residence in the corner of his head. 

_Are you two dating?_

They sit in their own bubble for almost two hours, quiet outside of a few comments Atsumu always feels the need to make in the drier moments, and Kiyoomi lets himself be at peace for the first time in a week. He likes peace.

Kiyoomi, unfortunately, is snapped back to reality as soon as the credits start to roll and Atsumu stretches his arms behind him with a yawn. The echoes of Komori are back, and Kiyoomi realizes, abruptly, that he’s never been a tactful person.

He looks over to Atsumu, arms still extended behind him, and tries to come up with the right words to summarize the inside of his head within the past week.

Atsumu looks back at him. He raises an eyebrow. Kiyoomi breaks.

“Are we dating? Is that what this is?”

Atsumu frowns, confused. “Huh?”

Kiyoomi doesn’t want to ask the question again. He almost wants to take it back the more he studies Atsumu's face and the way his eyebrows are winded together. He keeps his hands folded tight in his lap and his gaze steady, and he avoids the idea of having to repeat himself.

He sees Atsumu’s eyes widen in realization. “Shit.” He runs a hand through his hair, the frown still plastered on his face. “I didn’t mean- Fuck, I didn’t mean to come off that way. Did I come off that way? I’m really sorry.”

There’s an unfamiliar heaviness in Kiyoomi’s chest. He nods. It feels stiffer than usual.

“It’s alright. It was just something Komori mentioned, I wasn’t sure.” 

“Yeah, of course,” Atsumu replies, trailing off as gaze drifting down towards his fingernails. He starts to pick at the edges.

Kiyoomi wants to slap his hands away, scold him for messing up his pretty hands, and the silence in the room starts to become deafening. 

“I’m sorry.”

Atsumu looks up from his nails, face still stuck in the same expression. “No- It’s not your fault.” He starts to stand up, shaky. “It’s late. I should head home.”

Kiyoomi makes a weak noise in acknowledgement as he watches him go towards the doorway. He wants to stop him. He wants him.

Atsumu fumbles with his shoes with shaky hands and leaves his apartment with a speed like something was chasing him.

He calls Komori an hour later, once he finally lets his gaze on the door falter.

“Sakusa? What’s up?” There’s a rustling of something in the background. “This is late for you.”

“We’re not.” he says, quietly. “He said we’re not.”

“Oh. _Oh_.” 

Komori makes a sound, quiet and sad. Kiyoomi thinks it’s pity. He doesn’t want it, it’s the last possible thing he wants right now, but he feels too tired to snap at him. 

He looks back up at the door. He replays the image of Atsumu speeding out of it. “I think I love him.” 

“Kiyoomi…” Komori exhales, so quiet he barely hears it.

Whether or not he cries that night stays a secret between the two of them. He thinks that he’s let himself get too hot. That he’s winding away into nothingness.

\- 

Life goes on. 

Miya Atsumu avoids him like suddenly he’s the germaphobe in their situation, and Kiyoomi is merely a virus on the edge of his spectrum.

And he’s okay with this, he really is. Nothing is designed to last. He was lucky to have somebody that cared about him, just for a moment, but life is a fragile thing, and Kiyoomi has spent enough of his life trapped inside of his head to know just how easy, how comfortable it is to go back.

He bandages his burns. He’s fine.

He’s fine until Atsumu blatantly avoids sending him the winning point in a match, and he realizes he can’t take it anymore. He isn't fine.

Kiyoomi is not a violent person, he never has been, but for a second, he wants to watch Atsumu bleed the same way he cried, watch him understand exactly how pain feels when it's this deep.

Atsumu avoids looking him in his eyes when he apologizes for the toss. It’s weak and useless, and it gets disregarded the moment he walks away into the locker room.

He’s tired. He questions when his world stopped orbiting his anxieties and started orbiting Miya Atsumu. He questions if they’ve become the same thing.

Kiyoomi caves. He takes off the bandages on his burns and clicks on the gas stovetop, shoving himself directly next to the sparks. He shows up at Atsumu’s doorstep the next morning, knocking three times, sharp and loud, before he pushes his hands so deep into his jacket pockets that he worries he might break the seams. 

The feigned indifference on Atsumu’s face when he cracks open the door almost makes him want to take his hands out of his pockets and wrap them around his neck.

God, he’s in love with Miya Atsumu. 

They stare at each other for a minute too long, and it’s easy to tell that they’re both mentally running through the events of the last few weeks.

“Yes?” Atsumu asks, taunting as he breaks the silence.

Kiyoomi’s mouth starts moving before his brain can catch up. “Get over yourself. This is exhausting.” His mouth keeps going. “You threw your fit, now can we go back to normal?”

The indifference melts off Atsumu’s face and the gray circles under his eyes become obvious as he lets out a long breath. He’s avoiding Kiyoomi’s eyes. He looks as tired as Kiyoomi feels, and some of his anger dissipates.

“I’m sorry.”

He resists frustration. “That’s not an answer.”

Atsumu nods, more to him himself than to Kiyoomi, and says, “I know.” He finally makes eye contact. “Okay.” He opens the door a bit wider and steps back, an invitation to Kiyoomi. “I know it’s messy, but I have some of your tea if you want to come in.”

Kiyoomi nods and steps over the threshold. Steps back into the fire.

“Sure.”

Their conversation inside is stilted at best, resigned to only volleyball, and the fear of getting too comfortable lingers over their heads and in Kiyoomi's heart. He finishes his tea. He goes home. He sleeps an hour more than he did the night before. 

The next night, Atsumu video calls him, and the gray is gone from under his eyes. His smile is wide and warm as he goes on tangents about how he thinks America might have better beaches than Japan and how he saw a restaurant he wants them to try together one day. He says he missed having his best friend.

Kiyoomi is still in love with him, and there’s a heaviness in his chest that matches the blisters on his arms, but he’ll ignore them as long as he can see Atsumu smile. As long as Atsumu can keep him warm.

Komori tells him, after an EJP and MSBY match, that he should be careful, that leaving himself open by Miya Atsumu’s side will hurt him one day, worse than it has before, and Kiyoomi ignores him with a huff.

They have a routine, and routines have never hurt him before, and he forgets about Atsumu’s talent for shattering routines.

They’ve gone back to spending their rare days off the same- camped out on Kiyoomi’s couch while Atsumu puts in a disc of either an old match or a movie he insists they have to watch together. There’s the same loose thread on the edge of the couch, the same bag of onigiri on the coffee table, and the same mugs they use for tea. Nothing has changed.

And yet.

The strict two feet distance between them has shrunk. Atsumu is almost in the dead center of the couch, trying too hard to look casual, and the burn that Kiyoomi feels is stronger than it usually is.

He’s trying his hardest to keep his focus on the TV, holding the mug as tight as possible in his hand to distract from Atsumu’s proximity, letting the sound drown out his brain’s reminder of the heartache he’s learning to live with. But every time he looks over, Atsumu seems to be glancing at him. Staring. Marveling. 

He bites. “What.”

Atsumu has the mind to look guilty for a fraction of a second before his face resorts back to the blank and casual look it’s been holding for the past half hour. 

“We should kiss.” He says, sharp and sure of himself as he meets Kiyoomi’s eyes with fire in his own.

Kiyoomi is so _fucking_ tired of having the world stop around him because of Miya Atsumu. But it does. The world stops around him and for what seems like the millionth time, and his hands have made a home in the gas flame that is Miya Atsumu. He knows it’s bad, but is that really a surprise?

He exhales. There’s enough of him still functioning to ask, “Why?”

“Why not?” Atsumu says, shrugging like he doesn’t make a hobby out of playing with hearts.

His internal Komori is yelling at him, and he sets the mug down and clenches his fists for a second to make sure he’s still real. “Okay.” 

In the past year, he’s felt the fire on his hands move up his arms, move to his cheeks, and tonight, at this moment, he finally feels it on his lips.

He thinks, Miya Atsumu, this close and _real_ on top of him, is a wonder of a person that he can’t describe with just the idea of fires. 

They pull apart, and Kiyoomi feels like he needs a year to catch his breath. He looks at Atsumu, and there’s a dull look in his eyes that brands itself in Kiyoomi’s brain labeled with defeat. He feels heavier than he ever has.

He knows the answer, but he asks anyway. “What now?”

Atsumu sighs. “I don’t know.” He sits back against the edge of the couch and looks at the TV that's been off for the past fifteen minutes. “I really don’t.”

Kiyoomi thinks of hope. He thinks of hope and stovetops, hope and burned arms, hope and dull eyes. He breaks. “Fuck, Miya you can’t just say shit, _do_ shit, like that and say ‘I don’t know.’” He wishes he had the heart to yell.

Atsumu refuses to meet his eyes. “I’m sorry.”

“Can you leave?” He says, strained. He doesn’t know if he really wants him gone. He just knows he wants to stop feeling lost.

Atsumu sighs. “Okay." He stands up. "I’m sorry.”

It’s a mirror of what happened months ago, of Kiyoomi ruining his chances, of Atsumu running away, of Kiyoomi crying about just how cold he feels.

When Atsumu puts his shoes on, it’s steadier than it was, and he leaves in a way that’s slower and sadder than months ago.

Kiyoomi is left alone. He doesn’t want to call Komori and admit that he keeps letting himself burn.

He calls. 

Komori scolds him, as expected, but he lets Kiyoomi break over the line. He knows, now, to not give him pity.

He hates ending up like this, time and time again.

-

They go through another cold week. They play together fine, but don’t talk any more than absolutely necessary, and scatter their schedules enough to where they don’t even see each other in passing.

A cold week turns into a cold month. Kiyoomi refamiliarizes himself with loneliness. He makes a new routine and tries to stop letting himself orbit near a man that’s used him and forgot about him. _Atsumu_ becomes Miya again. 

A cold month turns into a freezing half of a year, and in an ideal world, Kiyoomi is healed. He tries to reach out to Wakatoshi, and he knows he’s the polar opposite of Miya, that he doesn’t play with feelings better than he plays volleyball, but the back of his mind sends off warning alarms that this is destined for failure too. He doesn’t reach out again.

He knows now, that he let himself get too hot. That he’s lost his structure. 

Their coach tells them that Miya got an offer from an American team to go play for a season or two. Maybe Kiyoomi is imagining the guilt in his expression, but maybe, for just once in their lives, Miya is feeling the weight of his actions.

He starts to phase his way out of their practices, starts to pack away his things in a few suitcases, and starts to leave indents in the lives of everyone he knows.

Kiyoomi realizes that he was never special.

Miya texts him goodbye. Says they should call while he’s gone. In return, Kiyoomi doesn’t see him away at the airport. 

Slowly, Miya’s Instagram becomes plastered with pictures of a pretty girl, short and American. She’s beautiful, the opposite of everything that Kiyoomi is, and he wonders if there’s another world in which he’s petite, blonde, and loved by Miya Atsumu.

There are days in which he gets calls that he ignores, and days in which he gets calls he picks up, just to see if it still hurts, while Miya talks on about the wonders of America and his new team. 

Kiyoomi pretends, each call, that he’s only a block away and that he’s stuck behind in time, long before he started burning and breaking apart. 

He tries to heal. Out of sight, out of mind, but always lurking. 

Familiar blisters have become nothing but scar tissue, and scar tissue eventually fades back to pale, regular, Kiyoomi, with the hint of a few moles. 

He stops picking up.

It’s dramatic, but he moves into a new apartment, a bit further from the gym so he can feel more like a regular human being instead of a shell of a volleyball player. Miya’s slippers get thrown out. Their mugs are left behind. The DVDs are given to Hinata. He cleans himself of Miya Atsumu.

He thinks, he hopes, that he’s free.

-

When Miya comes back two years later to join forces with the national team, his Instagram has been stripped of the girl, and he manages to look even more bright than he was when he left. He hates to admit it, but he’s still beautiful.

After their second practice, he leans against the locker next to Kiyoomi’s. Komori almost jumps him from behind. He notices that his grin, sly and stupid, is unchanged. 

“Say, Omi," He drawls, "I just finished moving into the new place if you want to come and visit.”

Kiyoomi thinks of how heat kills germs. He thinks of how he let the heat of Miya Atsumu kill part of his ability to love. His ability to trust. He thinks of the proteins inside of him breaking apart and falling to pieces, unable to function.

He smiles, sad and small. “I can’t.”

He means it in more ways than one.

**Author's Note:**

> atsumu i am so sorry for portraying you like that i want you to know that i love you more than anything and i wish i knew what was going on in ur head during this
> 
> but thank u so much for reading!! i am still very nervous about people associating the words that come out of my brain with me, so i don't know if i will post this on twitter or not, but u can find me lurking over there at @sktsism. thank u again and i hope u have a good rest of ur night or ur day and i hope u never have to get ur heart broken this way!! mwah
> 
> update as of november 22nd: the guy i wrote this abt is coming home from college for the holidays so uh. uhh lets see if i can channel my inner sakusa kiyoomi and Not pick up his calls teehee  
> update as of january 3rd: he got corona LMAO


End file.
